VSCode
IntelliSense
IntelliSense is a general term for various code editing features including: code completion, parameter info, quick info, and member lists.
IntelliSense features are sometimes called by other names such as "code completion", "content assist", and "code hinting."
Ctrl+Space
As provided by the language service, you can see quick info for each method by either pressing Ctrl+Space or selecting the > icon. The accompanying documentation for the method expands to the side. The expanded documentation remains available and updates as you navigate the list. You can close this by pressing Ctrl+Space again or by selecting the close icon.